The present invention relates to a humidifier and more particularly to a humidifier especially adapted for use in pulmonary assistance systems.
In pulmonary assistance systems wherein air, oxygen and/or medication are supplied to augment or enhance a patient's normal breathing, it often becomes desirable to add moisture to the air supplied to the patient. Heretofore, this has been accomplished by channeling the air being supplied past a container of water. The container is heated to raise the temperature of the water to increase the vaporization and the air is then passed over the water or a water-filled curtain, such as a wick, and water vapor is entrained in the air flow. Such devices have been designed for use at low pressures and at normal breathing rates and have been relatively large to meet the breathing needs of the user. In assistance systems which utilize a rapid sequence of short pulses of pressurized air or oxygen to achieve deep penetration within the pulmonary tract, the gas volume within the humidifier must be limited to ensure transmission of the high frequency pulses through the humidifier. If the gas volume within the humidifier exceeds a certain level, the high frequency pulses will be damped out within the humidifier rather than being transmitted to the patient. In addition, high frequency ventilation necessitates the use of higher pressures than occur at normal ventilation, so the humidifier apparatus must be a pressure vessel. The prior known devices generally do not meet these requirements and are, therefore, not suitable for use with high frequency ventilation systems.